ass 3

section .data
    ano db 10, "Assignment No. : 3", 10
        db "Positive / Negative elements from 64 bit array ", 10
    ano_len equ $-ano
    arr64 dq -21H, 5H, -33H, 61H, 62H
    n equ 5 ; n stores number of elements in array
    pmsg db 10, 10, "The number of positive elements from 64 bit array: "
    pmsg_len equ $-pmsg
    nmsg db 10, 10, "The number of negative elements from 64 bit array: "
    nmsg_len equ $-nmsg

section .bss
    p_count resq 1; reserves a quadword
    n_count resq 1
    char_ans resb 16

    %macro print 2
    mov rax, 1
    mov rdi, 1
    mov rsi, %1
    mov rdx, %2
    syscall
    %endmacro

    %macro exit 0
    mov rax, 60
    mov rdi, 0
    syscall
    %endmacro

section .text
    global _start

    _start:
        mov rsi, arr64 ; rsi points to the first element of array
        mov rcx, n ; n contains number of elements in array
        mov rbx, 0 ; counter for positive numbers
        mov rdx, 0 ; counter for negarive numbers

    next_num:
        mov rax, [rsi] ; take number in rax
        rol rax, 1 ; rotate by 1 bit to check sign in the CF
        jc negative ; jump to lavel negative if carry is generated

    positive:
        inc rbx ; CF=0 means positive number -> Increment positive count
        jmp next

    negative:
        inc rdx ; CF = 1 means negative number -> Increment negative count
    next:
        add rsi, 8 ; make rsi point to next number by adding 8 bytes
        dec rcx ; decrement counter of array elements
        jnz next_num
        mov [p_count], rbx ; Store Positive count
        mov [n_count], rdx ; Store Negative count
        print pmsg, pmsg_len
        mov rax, [p_count] ; Load value in p_count to accumulator
        call disp64_proc ; Call display procedure to display
        print nmsg, nmsg_len
        mov rax, [n_count] ; Load value in n_count to accumulator
        call disp64_proc ; Call display procedure to display
        exit

    disp64_proc:
        mov rbx, 10 ; Divisor 10 for decimal
        mov rcx, 2 ; No of digits
        mov rsi, char_ans + 1

        cnt:
        mov rdx, 0
        div rbx ; rbx = rbx/rax
        cmp dl, 09h ; Check if number lies between 0 to 9
        jbe add30
        add dl, 07

        add30:
            add dl, 30h ; Calculate ascii code
            mov [rsi], dl ; Store it in buffer
            dec rsi ; Point to one byte back
            dec rcx ; Decrement count
            jnz cnt ; Jump to cnt until count is not 0
            print char_ans, 2 ; Display result on screen
            ret